1. Field of the Invention
The present invention relates to a contactless synchronizer for sewing machines. The synchronizer according to the invention comprises at least two transmitting elements which are angularly displaced with respect to each other, which rotate with the sewing machine shaft and which indicate its angular position in cooperation with stationary sensing elements. The afore-mentioned sensing elements form parts of a circuit for producing control pulses as each transmitting element passes the respective sensing element.
2. Description of the Prior Art
A synchronizer of this type is disclosed in German OS 1 907 975 wherein two shutter disks with slots are mounted on the rotating shaft. In a position which is spaced apart from the sewing machine shaft there is disposed between the two disks a magnetic coil which serves as a transmitter and axially parallel with the magnetic coil serving as a transmitter there is disposed on the other side of each shutter disk a magnetic coil which serves as a receiver. The shutter disks are made of a material which screens the magnetic field between the transmitter and the receiver and thus a signal is only emitted in the receiver if there is a slot between the transmitter and the receiver.
This known synchronizer has proved extremely successful in use.